학술논문

Optimization of GaAs Solar Cell Performance and Growth Efficiency at MOVPE Growth Rates of 100 μm/h
Document Type
Periodical
Source
IEEE Journal of Photovoltaics IEEE J. Photovoltaics Photovoltaics, IEEE Journal of. 8(6):1596-1600 Nov, 2018
Subject
Photonics and Electrooptics
Gallium arsenide
Photovoltaic cells
Temperature measurement
Epitaxial growth
Surface morphology
Length measurement
high growth rates
metal–organic vapor phase epitaxy (MOVPE)
solar cells
III–V semiconductor materials
Language
ISSN
2156-3381
2156-3403
Abstract
III–V devices outperform all other solar cells in terms of efficiency. However, the manufacturing of these cells is expensive and prevents their use in a number of applications, which would benefit from the high efficiency. A major contribution to the cost is the metal–organic vapor phase epitaxy process for the III–V compounds. Increasing growth rates and, hence, machine throughput, as well as the growth efficiency, are important steps toward reducing the cost of III–V solar cells. We demonstrate the growth of GaAs solar cells at extremely high growth rates of 100 μm/h and achieve a V OC of 1.028 V, a base diffusion length of 6.5 μm, and an efficiency of 23.6% under AM1.5g conditions. Furthermore, we show reactor adjustments leading to growth rates up to 140 μm/h and reach conditions where more than half of the Ga from the precursor is incorporated into the solar cell layers. The results are encouraging and demonstrate a pathway toward lower cost III–V solar cell manufacturing.